Related papers: Third order correction to semileptonic $b\to u$ de…
The complete one-loop radiative corrections to third generation scalar fermions into gauge bosons Z and W^\pm is considered. We focus on \wt{f}_2 \to Z \wt{f}_1 and \wt{f}_i \to W^\pm \wt{f'}_j (f,f'=t,b). We include both SUSY-QCD, QED and…
The form factors of the semileptonic $B_c\to S(AV)\ell\nu$ $(\ell=\tau, \mu, e)$ transitions, where S and AV denote the scalar $X_{c0}$ and axial vector $(X_{c1}, h_{c})$ mesons, are calculated within the framework of the three-point QCD…
The form factors of the semileptonic $B_{q}\to D_{q}(J^{P}=0^{-})\ell\nu$ with $q=s, u, d$ transitions are calculated in the framework of three point QCD sum rules. Using the $q^2$ dependencies of the relevant form factors, the total decay…
In this paper we first calculate the form factors of $B \to (\pi,K)$ and $B_s \to K $ transitions by employing the perturbative QCD (pQCD) factorization approach with the inclusion of the next-to-leading-order(NLO) corrections, and then we…
We consider the decay of an intermediate mass Higgs boson into hadrons up to order O(\alpha_s^3). The results from the diagrams containing only light degrees of freedom were recently computed in a previous work by K.G. Ch. (Phys. Lett. B…
Utilizing asymptotic Pade-approximant methods, we estimate the three-loop order MS-bar coefficients of alpha_s^3[\log(\mu^2/m^2_b(\mu)]^k terms [k = {0,1,2,3}] within the $b \to u\ell^-\bar{\nu}_\ell$ decay rate. Except for the coefficient…
Semi-leptonic $B$ decays provide promising channels to test the Standard Model, search for signs of new physics, or determine fundamental parameters like CKM matrix elements. We present an update on our calculation of short distance…
The partial decay rate $\Gamma(Z\to b\bar{b})$ is significantly influenced by the mass of the top quark due to electroweak radiative corrections. The leading $\sim m_t^2$ and the next-to-leading contribution $\sim \ln m_t^2$ are known to be…
We present the study of the semileptonic decay \Lambda_c to \Lambda\ell^+\nu by using the light-cone sum rule approach. Distribution amplitudes (DAs) for the \Lambda baryon are discussed to the leading order conformal spin, and QCD sum rule…
We develop perturbative QCD factorization theorem for the semileptonic heavy baryon decay $\Lambda_b \to \Lambda_c l\bar{\nu}$, whose form factors are expressed as the convolutions of hard $b$ quark decay amplitudes with universal…
Recently, $O(\alpha^3)$ corrections to the muon decay rate and $O(\alpha_s^3)$ to heavy quark decays have been determined by Fael, Sch\"onwald, and Steinhauser. This is the first such perturbative improvement of these important quantities…
The FAC, PMS, and BLM optimization methods are applied to the QED corrections to the muon lifetime in the Fermi V-A theory. The FAC and PMS scales are close to m_e, while the BLM scale nearly concides with the geometric average \sqrt{m_e…
We study the $f^+$ form factor for the $\bar B_s\to K^+\ell^-\bar\nu_\ell$ semileptonic decay in a nonrelativistic quark model. The valence quark contribution is supplemented with a $\bar B^*$-pole term that dominates the high $q^2$ region.…
We compute the zero-recoil form factor for the semileptonic decay $\bar{B}^0\to D^{*+}\ell^-\bar{\nu}$ (and modes related by isospin and charge conjugation) using lattice QCD with three flavors of sea quarks. We use an improved staggered…
We present complete O(alpha_s^2) corrections to the decay b-->c+l+nu at the point where the invariant mass of the leptons sqrt{q^2} equals the c quark mass. We use this result, together with previously obtained corrections at the ends of…
We present a lattice-QCD calculation of the $B\to\pi\ell\nu$ semileptonic form factors and a new determination of the CKM matrix element $|V_{ub}|$. We use the MILC asqtad 2+1-flavor lattice configurations at four lattice spacings and…
I discuss the two-particle subleading power corrections in radiative leptonic $B \to \gamma \ell \nu$ decay at next-to-leading order in $\alpha_s$ with the dispersion approach. Employing the method of regions, factorization of the $B \to…
The 1/m_c and 1/m_b corrections to the \Lambda_b to \Lambda_c semi- leptonic decay are analyzed by QCD sum rules. Within the framework of heavy quark effective theory,the subleading baryonic Isgur-Wise func- tion of \Lambda_b to \Lambda_c…
Within the nonrelativistic QCD (NRQCD) factorization framework, we compute the order-$\alpha_s^3$ perturbative corrections to the leptonic decay of the $\Upsilon$ and $J/\psi$ with high numerical accuracy, at the lowest order in velocity…
The Fermi function $F(Z,E)$ accounts for QED corrections to beta decays that are enhanced at either small electron velocity $\beta$ or large nuclear charge $Z$. For precision applications, the Fermi function must be combined with other…